2021-2022 Audi Pre Sense Warning DTC B101C07

Symptoms

Owners of 2021-2022 Audi vehicles, including the Audi e-tron, may experience a sporadic "Seat belt warning" and/or "Pre Sense warning" message appearing in the driver information system (DIS) while driving. This issue is often accompanied by a specific diagnostic trouble code (DTC).

Fault Codes

When these warnings appear, workshops typically find the following DTC stored in the airbag control module/safety computer, identified as J234 (address word 0015):

Code	Description
B101C07	Driver seat belt switch mechanical malfunction

Diagnosis and Trigger Conditions

The Safety Computer (J234) continuously monitors the status of the seat belt latch switch (E24). If the system detects that the seat belt is continuously buckled—for example, if a seat belt extender or a seat belt cheat device is installed, or if the seat belt is simply left buckled—the Safety Computer receives a constant signal that the belt is latched. If this signal does not change within five consecutive drive cycles, the system assumes a seat belt cheat device is in use.

This condition then causes the DTC B101C07 to be stored and the "Pre Sense Warning" to appear in the DIS. A drive cycle, for the purpose of this diagnosis, involves a sequence of actions including unlocking/opening/closing the door, latching the seat belt, turning on the ignition and driving, parking, unlatching the seat belt, turning off the ignition, and opening/closing/locking the door.

Important Warnings

Audi explicitly states that "Parts replacement does not solve this issue. Claims for replaced parts will be subject to review." This means that replacing components like the seat belt latch switch will not resolve the underlying cause of the Audi e-tron Pre Sense warning and DTC B101C07, and such repairs may not be covered under warranty.

Additionally, a general safety warning is provided: "The risk of serious or fatal injury increases if the seat belt is not fastened, if it is worn incorrectly, or if it is damaged." Always refer to your owner's manual for proper seat belt usage and safety information.

Repair Procedure Summary

If your Audi vehicle exhibits the Audi e-tron Pre Sense warning or related seat belt warnings, and DTC B101C07 is found, the diagnostic process involves specific steps:

1. Connect to ODIS Service: A technician will connect the vehicle to the ODIS Service diagnostic system and perform a Guided Fault Finding (GFF) procedure.
2. Follow GFF Test Plans: If DTC B101C07 is stored in the airbag control module, the technician will follow all applicable GFF test plans to further investigate.
3. Customer Communication: If the GFF indicates that the seat belt latch switch is not defective, the customer will be informed that the use of a seat belt extender, a seat belt cheat device, or continuously buckled seat belt could be the cause of the concern.
4. Clearing the Warning: Performing one complete drive cycle that includes both latching and unlatching the seat belt is sufficient to change the DTC B101C07 from a static (permanent) fault to a sporadic (intermittent) one, and to turn off the "Pre Sense warning" in the instrument cluster.

Owner Action

If you are experiencing a "Seat belt warning" or "Pre Sense warning" in your 2021-2022 Audi, especially if you use a seat belt extender or frequently leave your seat belt buckled when not in use, consider these factors. It is recommended to visit an authorized Audi service center for proper diagnosis using ODIS Service. Be aware that replacing parts may not be necessary or effective for resolving the Audi e-tron Pre Sense warning and DTC B101C07.

Revision History

This Technical Service Bulletin, reference number 69 21 68 2056421/4, was issued on August 5, 2021. It supersedes Technical Service Bulletin Group 69 number 20-57, dated August 31, 2020. The bulletin has undergone several revisions:

• Revision 4 (August 5, 2021): Revised header, added Model Year.
• Revision 3 (September 1, 2020): Revised header, added MY20-21 Q7 & MY21 models.
• Revision 2 (February 6, 2020): Revised title.

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Source: NHTSA ID: 10200442